House settling repair costs when buying a house
Underpinning a settling foundation with piers can run $10,000 to $40,000. An engineer picks the fix: sealing, slab lifting or piers.
Updated · By 
Ben Sikes
How do you fix a house that's settling?
You fix what's moving the house first, then the damage it caused. A structural engineer tells you which is which. A slab crack that hasn't moved gets sealed for $200 to $1,000, while Fixr puts underpinning a sinking foundation at $10,000 to $40,000. Book the engineer before your inspection deadline, then ask the seller for the repair the engineer's report specifies.
Key takeaways
- Lifting a sunken slab with mudjacking costs far less than piers, but it isn't permanent. It doesn't fix what made the slab sink.
- Fixr prices pier types from $1,000 to $3,000, but the job total depends on the engineer's plan, so wait for a contractor's bid.
- Homeowners insurance generally won't pay for settling later. Get it priced now, inside this deal.
How much does it cost to fix a settling house?
| Repair | What it fixes | Cost |
|---|---|---|
| Crack sealing | A crack that hasn't moved | $200 to $1,000 |
| Mudjacking or slabjacking | A sunken slab, lifted from below | $500 to $1,900 |
| Pier types | The supports used in underpinning | $1,000 to $3,000 for the range of types |
| Underpinning with piers, whole job | A sinking foundation, excavated and supported | $10,000 to $40,000 |
Kept prices every line of an inspection report for $79, usually under 4 hours, and marks foundation movement as needing a professional quote, so you know this line waits on the engineer.
These are national figures from Fixr, which puts average slab repairs at $1,000 to $10,000. Slabs tend to be the cheapest foundation to repair.
Say the engineer calls for underpinning with piers. Fixr's job range is $10,000 to $40,000. Pier work with excavation will likely need a permit, which Fixr puts at $75 to $150, for $10,000 + $75 = $10,075 to $40,000 + $150 = $40,150. Fixr's pier figure of $1,000 to $3,000 is for the range of pier types, not a per-pier price, so it can't be multiplied by a pier count. Any soil or drainage work the engineer calls for comes on top. A contractor's written bid on the engineer's scope replaces this estimate.
Is house settling bad?
Some settling is normal. As This Old House puts it, "Foundation settling is normal, but not all movement is harmless." The worry is uneven settling, where one part of the house sinks faster than another. That's what cracks walls, sticks doors and slopes floors.
Warning signs, per This Old House:
- Cracks that are widening, or several of them.
- Horizontal or diagonal cracks, especially wider than 1/8 inch.
- Sloping floors together with doors or windows that stick.
- New gaps between walls, ceilings or floors.
A chimney leaning away from the house can point to the same problem (Fixr). See leaning chimney on an inspection report if yours is on the report.
How much is normal? An article for inspectors on the International Association of Certified Home Inspectors (InterNACHI) site says "shrinkage cracks are common in slab foundations, and are usually quite small" and that "many structural engineers agree that one inch of slope in twenty feet is tolerable." That is not a pass or fail test. A single visit cannot show whether the house is still moving, and only the engineer's read decides. This Old House adds that crack patterns and changes over time matter more than a single measurement. If a crack is widening or anything is still moving, treat it as a structural finding and get the engineer's read before you talk money.
Who figures out what's causing it?
Not your home inspector. InterNACHI tells its inspectors that diagnosing the cause of structural issues falls outside its standards, and to recommend a soil or structural engineer. That's who you hire.
An engineer doesn't sell the repair. Send the written scope to several foundation contractors and compare bids.
Structural engineer inspection before buying covers what the visit includes. How to get repair estimates during the inspection period covers every way to get a dollar figure before your deadline.
How do you fix a cracked slab foundation?
It depends on whether the slab only cracked or also moved.
- Cracked, not moved. The crack gets sealed with epoxy injection. Fixr says this gives a waterproof seal but isn't permanent.
- Sunk in one area. Mudjacking, or slabjacking, pumps grout under the slab to float it back up. Fixr says lifts like this aren't permanent, since they don't address the underlying issue.
- Still settling. Piers go down under the foundation, then hydraulics raise and hold it. Fixr calls underpinning a permanent solution.
Whatever the method, the cause comes first. The engineer tells you whether soil or drainage is behind it. For the other structural lines a report can flag, see foundation and structure findings on an inspection report.
What should you ask the seller for?
Ask for two things, in order: the engineer's evaluation, then the repair it specifies. Write it as one line: "living room slab crack with floor slope: structural engineer evaluation, then repair per the engineer's scope." Once a contractor bids that scope, put the bid in the request. Also ask for any past engineer reports, repair invoices and permits.
What to ask for after a home inspection shows how this line fits with the rest of your list. The buyer repair request letter template has the wording. Your contract sets the request deadline and whether you can cancel, so confirm both with your agent or attorney.
What if the seller won't pay for it?
Weigh it by what the engineer found. Sealing a stable crack is a small line. Settling that needs piers can run into five figures, and you won't have a firm number until a contractor bids.
If the seller refuses, counter with a credit or a lower price for the bid amount, or cancel if your contingency allows it. When to walk away after a home inspection shows how to decide.
Does homeowners insurance cover a cracked slab?
Usually not. Progressive says "foundation cracks or settling aren't covered by your homeowners policy" as a general rule, though damage from a covered peril such as a windstorm may be. Coverage varies by insurer and state, so ask your own insurance agent before your deadline.
Is settling worse in a new house or an old one?
Normal settling happens gradually as the soil under the house compacts under its weight. This Old House says homes under 10 years old may see more of it as the structure adjusts. In an older home, new cracks may point to a soil or drainage problem instead. The engineer tells you which one you have.
What if the engineer can't come before your deadline?
Ask your agent to request a short extension in writing. If you don't get one, send the request with the evaluation-then-repair line for the slab and real numbers on everything else. Before sending, confirm with your agent or attorney whether the contract still lets you cancel if the engineer later calls for piers. If it doesn't, decide on cancelling before the deadline.
While the engineer is booked, upload your inspection report to Kept and get the rest of your list priced.
Sources
Cost figures are modeled from public wage and materials data unless a line says observed. Kept is accountable for the numbers on this page, and corrections go to support@usekept.com. How we price.